A reference to the season 6 gag reel of the show Supernatural, in which actor Misha Collins was dared by his costar Jared Padalecki to eat a worm he found. Misha refused, and instead wore it as a wormstache.

Jared: "Eat it. I dare you to eat it. You have to eat it."
Misha: "I'm not going to eat it, that's disgusting. I'm going to wear it as a wormstache."
(Misha puts on the worm; J2 crack up)